import math

a = float(input("请输入第一条边:"))
b = float(input("请输入第二条边:"))
c = float(input("请输入角度"))
c = (math.pi / 180) * c
print(c)
answer = a * a + b * b - 2 * a * b * math.cos(c)
e = math.sqrt(answer)
print('第三条边为:',e)
